The present invention provides an apparatus and control circuit for transfer of parts between a first manufacturing operation and a second manufacturing operation.
More specifically, the present invention provides a gripper jaw assembly to grasp and separate a plurality of chain link plates from a first pressing or stamping operation for their transfer to a second manufacturing operation. The link plates may be in a continuously advancing line of link plates being discharged from a press operation. The gripper jaw assembly is mounted on the distal end of a robotic apparatus with a flexible arm, which gripper jaw is pivotable at the flexible arm end. The proximal end of the flexible arm apparatus is secured to and pivotable about a base, which may be secured to a floor or otherwise permanently mounted. The several assemblies or operations, that is the gripper jaw assembly, the flexible arm, the first press and the second press, are mechanical elements having a plurality of strategically positioned sensors, which sensors are coupled to a central processing unit (CPU) or computer, either directly or through controllers, for control of the operations, sensors and apparatus. The computer is operable to receive signals from any of the sensors and controllers and to communicate control signals to the controllers and operating elements in response to the sensed signals.
Robotic apparatus for manufacturing processes are utilized in various industries and technologies. The specific uses for such robotic apparatus include computer-controlled automatic welding machines in the automotive industry, as well as multi-spindle drilling apparatus for machining industries. Other known uses include assembly and grinding operations. However, all of these applications of such flexible arm or robotic apparatus require operating heads for the specific automated task. The flexible arm of the robotic apparatus provides a large range of motion and a plurality of potential distal end locations in a three-dimensional array of positions. Use of the flexible arm removes an operator from potentially harmful locations in proximity to moving, spinning, pressing, punching or welding operations, and it provides a means to reduce the labor-hours per operation as an economic benefit. Illustrations of such flexible arm apparatus are various models from ABB Flexible Automation Inc. of New Berlin, Wis. noted as IRB 2400. These assemblies and apparatus are described in a brochure, Maestro System 4 Product Line, of May 1996.
The manufacture of roller-chain link plates and chains of all types can involve a large number of mechanical operations. As an example, roller chain manufacture utilizes multiple high-speed presses, which may include sequential punch press operations, to generate the link plates. Other operations may include drill presses, riveting equipment, welding, cold-heading and turning equipment. Each of these mechanical activities can be a high-speed operation, which can present a potential hazard to an operator. Consequently, there have been continuous attempts to automate various steps or operations in manufacturing practices to minimize the danger to employees, as well as to speed the processing activity. As noted above, automating the repetitive steps of the manufacturing process takes an operator out of a potentially hazardous location, for example, it moves an operator away from a punch press operation. Other potentially dangerous operations include drill presses and welding operations. In addition to the health and safety benefits from the automation of manufacturing operations, economic benefits accrue from the use of machinery to perform repetitive tasks previously performed by manual labor.
Acquisition and automatic transfer of relatively small parts between manufacturing operations requires technique, unique tooling, machine and transfer equipment speed, and tooling dexterity. These are requisite attributes as small parts manufacture is frequently a high-volume or high-speed operation. The tooling must be reliable and agile to handle the parts, and operational techniques may require accommodating parts acquisition by tooling in a physically demanding or constrained environment. In the case of link plates for roller chain, each plate may be less than one inch in length with a wall thickness less than one-quarter inch. The link plates will be formed with an hour-glass shape, which physical characteristics are not conducive to being grasped by a large mechanical apparatus. Therefore, the operational techniques and, the ancillary handling and transfer equipment or tooling become necessary elements in the automation-of-manufacturing equation.